provided you give appropriate credit to the original author(s) and the source, provide a link ... 1 Department of Epidemiology, University of Michigan School of Public ...... 5 Department of Osteopathic Medical Specialties, College of Osteopathic.
Malaria Journal
Coalson et al. Malar J (2016) 15:527 DOI 10.1186/s12936-016-1587-9
Open Access
RESEARCH
High prevalence of Plasmodium falciparum gametocyte infections in school‑age children using molecular detection: patterns and predictors of risk from a cross‑sectional study in southern Malawi Jenna E. Coalson1* , Jenny A. Walldorf2, Lauren M. Cohee2, Miriam D. Ismail1, Don Mathanga3, Regina Joice Cordy4, Matthias Marti4, Terrie E. Taylor5, Karl B. Seydel5, Miriam K. Laufer2 and Mark L. Wilson1
Abstract Background: In endemic areas, many people experience asymptomatic Plasmodium infections, particularly older children and adults, but their transmission contribution is unknown. Though not the exclusive determinant of infectiousness, transmission from humans to mosquitoes requires blood meals containing gametocytes. Gametocytes often occur at submicroscopic densities, challenging measurement in human populations. More sensitive molecular techniques allow better characterization of gametocyte epidemiologic patterns. Methods: Approximately 30 households were selected from each of eight sites in southern Malawi during two crosssectional surveys. Blood was sampled from 623 people during the dry season and 896 the following rainy season. Among people PCR-positive for Plasmodium falciparum, mature gametocytes were detected by qRT-PCR. Regression models evaluated predictors of gametocyte carriage and density in the total population and among those with PCRpositive infections. Results: The prevalence of gametocyte carriage by molecular testing was 3.5% during the dry season and 8.6% during the rainy season, and by microscopy 0.8 and 3.3%, respectively. Nearly half of PCR-positive infections carried gametocytes, regardless of recent symptom status. Among P. falciparum-infected people, only living in unfinished houses and age were significantly associated with gametocyte presence. Infected people in unfinished houses had higher odds of carrying gametocytes (OR 2.24, 95% CI 1.16–4.31), and 31% (95% CI 3–65%) higher gametocyte density than those in finished houses. School-age children (5–15 years), had higher odds than adults (≥16 years) of having gametocytes when infected (OR 2.77, 95% CI 1.47–5.19), but 31% (95% CI 11–47%) lower gametocyte density. Children
